Computer Watch ,

RICHARD MOROCHOVE

Toronto Star - Monday January 24^th 2005

Digital photography gives us more flexibility to edit and crop photos. We also can decide how we're going to print our precious images.

That's where matters quickly become more complicated.

Most film photographers outsource developing and print making to photo labs. But when we print our photos, we need to know more about what goes into the making of a good print

It's relatively easy to judge if a digital photo print meets our standards for colour reproduction and resolution. It's far more difficult to assess resistance to colour fading. Two freshly created prints may look equally good. One may fade after as little as five years, while the other will look good for 50 or more years.

What goes into making a print that will last for decades? It’s a combination many factors including the printer, ink and paper used. Here are some tips to consider if you want your home made photos to last for decades.

Research your photo printer before you purchase it. Some printers are designed mainly for ease of use and convenience. They're great for printing photos to casually share with friends, but don't expect the pics to last if you display them on your wall.

You may wonder how a printer manufacturer, can assert its prints will last for decades, when the printer that creates them has been available for just a few months. The secret is accelerated aging tests. Photographic prints are exposed to high intensity Xenon light, 24 hours a day.

I’ve visited a colour fading test lab and wished I wore sunglasses for my peek inside the light box containing the test prints. Using the high intensity light, 65 years of normal exposure to be light on a living room can simulated in only 24 weeks.

According to Wilhelm. Imaging Research (WIR), photos produced by some Sony printers (DPP-EX5, DPP-EX7, DPPEX50) will suffer from noticeable fading in just four years. On the other hand, photos created by Epsons PictureMate Personal! Photo Lab will last l04 years before fading.

WIR founder Henry Wilhelm wrote the definitive book on colour fading, The Permanence and Care of Color Photographs. The book is available for free downloading in a series of PDF files on his firm’s website (wilhelmresearch.com). I recommend perusing this website to learn more about colour fading.

Just as important as the choice of printer are the inks and paper you use with it You can safely save money using refilled black ink cartridges for business documents. But don’t trust your valued photos to third party inks. Use the printer manufacturers ink and recommended photo paper for best results.

Once you create your print its colour permanence is affected by several importan factors, including exposure to light and ozone, temperature and humidity. The lower the exposure the better, when it comes to retarding colour fade.

Unless you move, you probably can't do much about the level of ozone, an air pollutant. However you can consider the other three factors.

A print stored in a photo album will last longer than one on your wall, which is exposed to more light. If you display a print, keep it out of direct sunlight. Mounting it under glass helps too.

Low temperatures and low humidity retard colour fading. If all other factors stay the same, lowering the storage temperature from 24C to 19C doubles the length of time before fading becomes noticeable, assuming a relative humidity of 40 per cent. If you lower the temperature to -26C, prints last 1,000 times longer before fading than those stored at 24C.

Wilhelm was a consultant to, Corbis, the stock image archive company owned by Microsoft co-founder Bill Gates. Based on his advice, Corbis images were moved from an office building in New York City and are now stored underground in a former limestone mine. They are maintained in filing cabinets in dark rooms. The most important photographs are stored at temperatures below -18C.

Unfortunately, there is still no generally accepted standard for measuring colour fade. A photo paper that brags of a 100-year display life in a banner headline on the front of the package, may use the fine print on the back of the box to list unrealistic conditions backing that claim.

Wilhelm is particularly critical of the way Kodak rates its photographic paper for inkjet printers. Kodak’s display life predictions for Ultima Picture Paper are based upon exposure to significantly lower levels of light than those used by most other sellers of photographic paper. Kodak also assumes the light source is covered by an ultraviolet filter and the print is exposed to lower levels of humidity.

As a result, Kodak’s display life predictions for its paper are almost 15 times longer than those estimated by the more conservative tests conducted by WIR.

Richard Morochove, FCA, is a Toronto-based computer consultant. E-mail comments to cornputerwatch@morochove.com.